The correct answer is option 'C', which means that both sugarcane in Malaysia and coffee in Brazil provide immediate cash to the farmers.

Explanation:
1. Tea in Assam:
Tea is a monoculture crop grown in Assam, India. While it is a major cash crop, it does not provide immediate cash to the farmers. The tea leaves need to be harvested, processed, and then sold, which takes time. Therefore, tea in Assam does not fulfill the criteria of providing immediate cash to the farmers.

2. Rubber in Africa:
Rubber is another monoculture crop grown in various countries in Africa. Similar to tea, rubber does not provide immediate cash to the farmers. The rubber trees need to mature and be tapped for latex, which is then processed into rubber sheets. This process takes time, and the farmers have to wait for the latex to be processed and sold before they receive cash.

3. Sugarcane in Malaysia:
Sugarcane is a widely cultivated monoculture crop in Malaysia. It is known for providing immediate cash to the farmers. Once the sugarcane is harvested, it is taken to sugar mills where it is crushed to extract the juice. The juice is then processed to obtain sugar, which is sold in the market. The farmers receive immediate cash for their sugarcane upon selling it to the sugar mills.

4. Coffee in Brazil:
Brazil is one of the largest producers and exporters of coffee in the world. Coffee cultivation provides immediate cash to the farmers. The coffee cherries are harvested, processed, and then sold either as green coffee beans or roasted coffee. Farmers can sell their coffee crop immediately after processing, which allows them to receive cash without any significant delay.

In conclusion, while tea and rubber do not provide immediate cash to the farmers, sugarcane in Malaysia and coffee in Brazil fulfill the criteria and provide immediate cash to the farmers. Hence, the correct answer is option 'C', which includes sugarcane in Malaysia and coffee in Brazil.